Friction gearing



FRICTION GEARING Dec. 11, 1923.

Filed Sent. 14 1922 Inman to@ atroz naw einen I Farc D. GIBBS, OF LOUISVILLE, KENTUCKY.

FBICTIOISI' GEARING.

Continuation of application led January 29, 1921,` Serial No. 440,968. This application led September To all 'w1/tom it may concern: `1

Be it known that I, JAMES D. GIBBS, a citizen of the United States, and resident of Louisville in the county of Jefferson and State of kentucky, have invented certain new and useful Improvements in Friction Gearing, of which the following is a. specification.-

This application is a continuation of an pplication filed by me on the 29th day of anuary, 1921, Serial No. 440,968.

My invention relates to friction gearing and is shown and described herein as embodied in speed control mechanism designed more especially for what is commonly known as sensitive drills, in the operation of which the exact eiect or action of the drill upon the metal being rforated is communicated to the operator through the hand and arm, thus serving as a, guide as to the amount of pressure and s d that can safely be applied, but applicable also to lathes and many other devices.

The invention aims to provide a friction gearing which will be economical of construction, non-slippin in its action, durable in use, and capable o being easily manipulated.

An embodiment ofmy invention is illustrated in the accompanying drawings, in whichzp Figure 1 is a side elevation of the pertinent portion of a drill press embodying my invention.

Fig. 2 is a front view sectioned on broken line :v-w.

Fig'. 3 is a plan view of the speed control mechanism.

Fig. 4 is an enlarged portion of cone-wheel and communicating disc fully meshed.

Similar parts are indicated by identical letters in the several views.

The general form of the main frame A may ybe similar to :that of the ordinary bench-drill except that in addition to the bearing or housing A', for the drill spindle c, it is provided with an additional bearing A, for the vertical shaft d, (the latter being arallel with the drill spindle'c), and the tion to vertical shaft by means ofthe mitre-gears 1-1.

.In point of construction, the drill/spindle and its related parts 'are not diii'ere'nt from 14, 1922. serial 10.588,264.

those commonly in use, viz; the main housing A', the key-seated spindle o with its thrust. bearing c, the vertically moving sleeve f having its rack within the housing,

the shaft g with its feed disc h, detachable handle z', and internal gear meshing with rack on the sleeve f, and, lastly, the chuck e for attaching the drills of any desired size.

. Instead of an ordinary pulley or wheel being mounted on the spindle c, I employ a cone-shaped pulley a, having a series of V-shaped grooves 'n n, of varying diameters,

exerting an inward pressure by means of spring s, is the` sliding arm D, upon which is carried a bevelededge disc or wheel o, which is adjustably adapted to contact with the corresponding grooves of the conewheels L and b, thereby communicating the motion to the drill in any degree of speed desired.'

I have found that two factors are necessary to a successful friction gear of the ty in which a wedge'shaped or beveled edged friction wheel cooperates with a correspondingly grooved wheel. One is that the coacting walls must be steeply inclined, and the other that the peripheral edge of the beveled edged wheel must at no time contact with the bottom of the co-acting groove.

The inclination which I have found most 'tween the periphervf of the beveled edged wheel and the bottoms of the grooves, so that there is no rolling Contact, but only a wedging action.

The ,several parts of. my speed control mechanism may be constructed of any suitoved cone-pulleys or wheels and papiermch or fibre for the beveled edged wheel o. Cbviously the material for the disc able material, preferably cast iron for the ari r plate B for the horizontal shaft. -k whic is connected with and imparts mo ion `should be somewhat'softer than that of the cone-pulleys or wheels and although fibre Aals ties of tenacity and durability, other material havin in s'uicient degree the samtl qualities may e successfully applied.

It will be observed that the arm D upon which the beveled edged wheel o, is mounted, slides up and down on the curved stud p, one end of which is rigidly connected with the plunger m, which has its bearing in the sleeve C. The tubular plunger m, has its .free end plugged and a spiral spring s,'with vupon the springs causesthe plunger to rec ede forcing the beveled edged wheel into firm contact with the adjacent grooves of the two cone-wheels. To provide lateral movement4 to the beveled edged wheel, in order that it may have equally firm contactwith both of the cone1whee1s`,the arm D has a free rotating movement upon the stud p, thus automatically adjusting the beveled' edged wheel to any pair of the "grooves This is best illustrated in Fig. 3;

What I claim is 1. A variable speed mechanism comprising two reversely placed multi-grooved cone wheels journaled on parallel axes, the grooves of said wheels being of narrow V- shape in cross section, and an idle wheel ofv softer material, having a periphery of narrow reversed V-shape in cross section, the walls of the grooves and idle wheel being so disposed that the idle wheel will be supported by the coacting grooves oft-he cone wheels with its peripheral edge spaced from the bottom of said grooves, and 'means for pressing Said idle wheel towards and into contact with both of said cone Wheels whereby itis entered into the grooves therein with a wedging action.

2. A variable speed mechanism comprising two reverse] placed multi-grooved. cone wheels journale on parallel axes, a, member mounted to have reciprocating motion towards and from a plane common to said axes, said member carrying a part extending parallel to said axes, a bracket arm slidably carried by said part and having a suitable operatin handle, an idle wheel rotatably carried y said bracket arm, and adapted to engage the grooves of said cone wheels, and spring means acting on said slidable member to press the idle wheel towards v the cone wheels.

3. In a variable speed mechanism, a support, parallel shafts journaled therein, re-

versely arranged grooved friction cone` wheels fast on said shafts, said support having a passage substantially perpendicular .to a plane passing throu h both. said shafts, a tubular member slidably held in said passage and having lengthwise .slots in Vits walls, a transverse pin passing through s aid slots and engaging the support, a spring within the tube and confined between said in and tube end, a guide member carried liy said tubular member and extending parallel to said parallel shafts, and an idle wheel slidably supported from said guide member.'

`4. lA variable speed mechanism comprising two reversely placed multi-grooved cone wheels journaled on .parallel axes, the grooves of said wheels being of narrow V- shape in cross section, and an idle vwheel yieldingly and slidably mounted on a parallel shaft and having a peripheral edge of narrow reversed V-shape in crosssection to correspond to the grooves in said cone wheel;

5. A variable speedmechanism comprising two reversely placed multi-grooved cone wheels journaled on parallel axes, the grooves of said wheels being of narrow V- sha e in cross section, and an idle wheel I y yie dingly and` slidably mounted on a parallel shaft and having a peripheral edge of narrow reversed V-shape in lcross section to correspond to the grooves in said cone wheel, the walls of the grooves and con'e wheel being so disposed that the idle wheel will be supported by the walls of the corresponding grooves with its peripheral edge spaced from the bottoms of the grooves.'

6. In power transmission mechanism a wheel having a narrow V-shaped groove the walls of which are disposed at an angle to each other of not over 25, and a coacting beveledv edged wheel the walls of which are positioned at a corresponding, angle, and means for rotatably supporting said wheels -`with the beveled edge of the latter meshing with the groove in the former.

7. In a power transmission mechanism, a suitably journaled wheel having a narrow V-shaped groove the walls of which are disposed at an angle of not over 25 and a suitably journaled beveled edged wheel having its beveled edges disposed at a corresponding angle, said last named wheel having its beveled edge engaging the groove in said first named wheel and its peripheral edge spaced from the bottom of the groove.

8. A power transmission mechanism comprising a wheel having a narrow vil-shape groove and a correspondingly beveled wheel of softer material so disposed that its side surfaces contact with and are supported by the coacting side walls of the groove inthe grooved wheel and having its peripheral edge spaced from the bottom of said groove, and

ion

Memes means for pressing said beveled wheel into contact wit said groove.

9. A power transmission mechanism comprising two correspondingly grooved wheels, the said grooves be' of narrow V-shape with the respective wa posed at an angleto each other of substantially 18, and an idle Wheel of softer material having a periphery of narrow reversed V-shape in cross section with the walls thereof linclined to the same degree as the walls of said grooves so disposed that of the grooves dis salad walls of the idle, pulley come with and are supported by the coacting side walls 4of the grooved wheels, saiddle pulley having its peripheral edge spaced from the bottoms of the grooves in said grooved wheels, and means for pressing said idle wheel into the grooves of said grooved wheels. i

In testimony whereof, I aix my signature.

. .TES '1). GIBBS. 

